MYSTERY surrounds how a healthy mum died in agony just days after giving birth via an emergency C-section.

Tammy Nathan-Belk, 25, gave birth to a baby girl Koraleigh via emergency C-section, which was her fourth child.

Ms Nathan-Belk’s other births had been without complications, with the woman released from hospital a few days after the C-section to continue her recovery and rest at home, the New Zealand Herald reports.

According to Ms Nathan-Belk’s devastated mum, Tania Belk, her condition "deteriorated rapidly" on the day she died.

She told news outlet Stuff: "She was having pains in her stomach so saw her local GP and was given painkillers.

"It all happened so fast from there, she was at home and was suddenly in agony.

"Troy called an ambulance, but she died on her way to hospital.

"We were told her body had rejected the internal stitches from the C-section and it caused acute appendicitis."

We don’t want this to happen to another family. She was a healthy, strong young woman that should have never left us

A preliminary post-mortem examination suggests Ms Nathan-Belk’s cause of death may have been a ruptured acute appendicitis.

But further investigations need to take place for an accurate diagnosis and this may take months, leaving her family without answers.

Ms Belk said she did not blame anyone for her daughter’s death but still wanted to know why she died.

She said: "We don’t want this to happen to another family. She was a healthy, strong young woman that should have never left us."

What is a Caesarean section?

About one in five babies born in Britain are delivered by a C-section.

To carry out the operation, a cut is made across the tummy, allowing surgeons access to the womb.

Caesareans can be life-threatening, so doctors will only recommend it if it’s the safest option for pregnant women and their babies.

The name is thought to be linked with Julius Caesar, but he is believed to have been born naturally.

His mother, Aurelia, is reported to have been alive for most of his life, which means it’s unlikely she underwent a caesarean.

The word is most likely derived from the Latin word to cut, which is caesus, the past participle of caedere.

And the word lent its name to a law, the Lex Caesaria, which ruled that if a pregnant woman died the unborn baby should be cut from her.

Established around 715-673 BC, it was in force hundreds of years before Julius Caesar was born.

A Counties Manukau Health spokesman told Stuff any deaths happening under their care would be investigated.

A statement said: "All serious events, including unexpected deaths, are investigated by the DHB, and any maternal case is also reported to a national perinatal mortality committee for independent review."

A Givealittle fundraiser has now been established in Ms Nathan-Belk’s memory to help provide for her four kids, who are all under ten.